import objectAssign from '@cci/cui/lib/utils/merge.js'
import { markNodeData, NODE_KEY } from './util'

export const getChildState = node => {
  let all = true
  let none = true
  let allWithoutDisable = true
  for (let i = 0, j = node.length; i < j; i++) {
    const n = node[i]
    if (n.checked !== true || n.indeterminate) {
      all = false
      if (!n.disabled) {
        allWithoutDisable = false
      }
    }
    if (n.checked !== false || n.indeterminate) {
      none = false
    }
  }

  return { all, none, allWithoutDisable, half: !all && !none }
}

const reInitChecked = function(node) {
  if (node.childNodes.length === 0) return

  const { all, none, half } = getChildState(node.childNodes)
  if (all) {
    node.checked = true
    node.indeterminate = false
  } else if (half) {
    node.checked = false
    node.indeterminate = true
  } else if (none) {
    node.checked = false
    node.indeterminate = false
  }

  const parent = node.parent
  if (!parent || parent.level === 0) return

  if (!node.store.checkStrictly) {
    reInitChecked(parent)
  }
}

const getPropertyFromData = function(node, prop) {
  const props = node.store.props
  const data = node.data || {}
  const config = props[prop]

  if (typeof config === 'function') {
    return config(data, node)
  } else if (typeof config === 'string') {
    return data[config]
  } else if (typeof config === 'undefined') {
    const dataProp = data[prop]
    return dataProp === undefined ? '' : dataProp
  }
}

let nodeIdSeed = 0

export default class Node {
  constructor(options) {
    this.id = nodeIdSeed++
    this.text = null
    this.checked = false
    this.indeterminate = false
    this.data = null
    this.expanded = false
    this.parent = null
    this.visible = true

    for (const name in options) {
      if (options.hasOwnProperty(name)) {
        this[name] = options[name]
      }
    }

    // internal
    this.level = 0
    this.loaded = false
    this.childNodes = []
    this.loading = false

    if (this.parent) {
      this.level = this.parent.level + 1
    }

    const store = this.store
    if (!store) {
      throw new Error('[Node]store is required!')
    }
    store.registerNode(this)

    const props = store.props
    if (props && typeof props.isLeaf !== 'undefined') {
      const isLeaf = getPropertyFromData(this, 'isLeaf')
      if (typeof isLeaf === 'boolean') {
        this.isLeafByUser = isLeaf
      }
    }

    if (store.lazy !== true && this.data) {
      this.setData(this.data)

      if (store.defaultExpandAll) {
        this.expanded = true
      }
    } else if (this.level > 0 && store.lazy && store.defaultExpandAll) {
      this.expand()
    }
    if (!Array.isArray(this.data)) {
      markNodeData(this, this.data)
    }
    if (!this.data) return
    const defaultExpandedKeys = store.defaultExpandedKeys
    const key = store.key
    if (key && defaultExpandedKeys && defaultExpandedKeys.indexOf(this.key) !== -1) {
      this.expand(null, store.autoExpandParent)
    }

    if (key && store.currentNodeKey !== undefined && this.key === store.currentNodeKey) {
      store.currentNode = this
    }

    if (store.lazy) {
      store._initDefaultCheckedNode(this)
    }

    this.updateLeafState()
  }

  setData(data) {
    if (!Array.isArray(data)) {
      markNodeData(this, data)
    }

    this.data = data
    this.childNodes = []

    let children
    if (this.level === 0 && this.data instanceof Array) {
      children = this.data
    } else {
      children = getPropertyFromData(this, 'children') || []
    }

    for (let i = 0, j = children.length; i < j; i++) {
      this.insertChild({ data: children[i] })
    }
  }

  get label() {
    return getPropertyFromData(this, 'label')
  }

  get icon() {
    return getPropertyFromData(this, 'icon')
  }

  get key() {
    const nodeKey = this.store.key
    if (this.data) return this.data[nodeKey]
    return null
  }

  get disabled() {
    return getPropertyFromData(this, 'disabled')
  }

  get nextSibling() {
    const parent = this.parent
    if (parent) {
      const index = parent.childNodes.indexOf(this)
      if (index > -1) {
        return parent.childNodes[index + 1]
      }
    }
    return null
  }

  get previousSibling() {
    const parent = this.parent
    if (parent) {
      const index = parent.childNodes.indexOf(this)
      if (index > -1) {
        return index > 0 ? parent.childNodes[index - 1] : null
      }
    }
    return null
  }

  contains(target, deep = true) {
    const walk = function(parent) {
      const children = parent.childNodes || []
      let result = false
      for (let i = 0, j = children.length; i < j; i++) {
        const child = children[i]
        if (child === target || (deep && walk(child))) {
          result = true
          break
        }
      }
      return result
    }

    return walk(this)
  }

  remove() {
    const parent = this.parent
    if (parent) {
      parent.removeChild(this)
    }
  }

  insertChild(child, index, batch) {
    if (!child) throw new Error('insertChild error: child is required.')

    if (!(child instanceof Node)) {
      if (!batch) {
        const children = this.getChildren(true)
        if (children.indexOf(child.data) === -1) {
          if (typeof index === 'undefined' || index < 0) {
            children.push(child.data)
          } else {
            children.splice(index, 0, child.data)
          }
        }
      }
      objectAssign(child, {
        parent: this,
        store: this.store
      })
      child = new Node(child)
    }

    child.level = this.level + 1

    if (typeof index === 'undefined' || index < 0) {
      this.childNodes.push(child)
    } else {
      this.childNodes.splice(index, 0, child)
    }

    this.updateLeafState()
  }

  insertBefore(child, ref) {
    let index
    if (ref) {
      index = this.childNodes.indexOf(ref)
    }
    this.insertChild(child, index)
  }

  insertAfter(child, ref) {
    let index
    if (ref) {
      index = this.childNodes.indexOf(ref)
      if (index !== -1) index += 1
    }
    this.insertChild(child, index)
  }

  removeChild(child) {
    const children = this.getChildren() || []
    const dataIndex = children.indexOf(child.data)
    if (dataIndex > -1) {
      children.splice(dataIndex, 1)
    }

    const index = this.childNodes.indexOf(child)

    if (index > -1) {
      this.store && this.store.deregisterNode(child)
      child.parent = null
      this.childNodes.splice(index, 1)
    }

    this.updateLeafState()
  }

  removeChildByData(data) {
    let targetNode = null
    this.childNodes.forEach(node => {
      if (node.data === data) {
        targetNode = node
      }
    })

    if (targetNode) {
      this.removeChild(targetNode)
    }
  }

  expand(callback, expandParent) {
    const done = () => {
      if (expandParent) {
        let parent = this.parent
        while (parent.level > 0) {
          parent.expanded = true
          parent = parent.parent
        }
      }
      this.expanded = true
      if (callback) callback()
    }

    if (this.shouldLoadData()) {
      this.loadData((data) => {
        if (data instanceof Array) {
          if (this.checked) {
            this.setChecked(true, true)
          } else {
            reInitChecked(this)
          }
          done()
        }
      })
    } else {
      done()
    }
  }

  doCreateChildren(array, defaultProps = {}) {
    array.forEach((item) => {
      this.insertChild(objectAssign({ data: item }, defaultProps), undefined, true)
    })
  }

  collapse() {
    this.expanded = false
  }

  shouldLoadData() {
    return this.store.lazy === true && this.store.load && !this.loaded
  }

  updateLeafState() {
    if (this.store.lazy === true && this.loaded !== true && typeof this.isLeafByUser !== 'undefined') {
      this.isLeaf = this.isLeafByUser
      return
    }
    const childNodes = this.childNodes
    if (!this.store.lazy || (this.store.lazy === true && this.loaded === true)) {
      this.isLeaf = !childNodes || childNodes.length === 0
      return
    }
    this.isLeaf = false
  }

  // setChecked(value, deep, recursion, passValue) {
  //   this.indeterminate = value === 'half'
  //   this.checked = value === true

  //   if (this.store.checkStrictly) return

  //   if (!(this.shouldLoadData() && !this.store.checkDescendants)) {
  //     const { all, allWithoutDisable } = getChildState(this.childNodes)

  //     if (!this.isLeaf && (!all && allWithoutDisable)) {
  //       this.checked = false
  //       value = false
  //     }

  //     const handleDescendants = () => {
  //       if (deep) {
  //         const childNodes = this.childNodes
  //         for (let i = 0, j = childNodes.length; i < j; i++) {
  //           const child = childNodes[i]
  //           passValue = passValue || value !== false
  //           const isCheck = child.disabled ? child.checked : passValue
  //           child.setChecked(isCheck, deep, true, passValue)
  //         }
  //         const { half, all } = getChildState(childNodes)
  //         if (!all) {
  //           this.checked = all
  //           this.indeterminate = half
  //         }
  //       }
  //     }

  //     if (this.shouldLoadData()) {
  //       // Only work on lazy load data.
  //       this.loadData(() => {
  //         handleDescendants()
  //         reInitChecked(this)
  //       }, {
  //         checked: value !== false
  //       })
  //       return
  //     } else {
  //       handleDescendants()
  //     }
  //   }

  //   const parent = this.parent
  //   if (!parent || parent.level === 0) return

  //   if (!recursion) {
  //     reInitChecked(parent)
  //   }
  // }

  setChecked(value, deep, recursion, passValue) {
    // 父节点不影响子节点，但是子节点影响父节点
    if (this.store.checkParent) {
      // !this.store.checkcheckStrictly && (this.store.checkcheckStrictly = false)

      if (!this.isLeaf) {
        const { all, half } = getChildState(this.childNodes)
        let childCheckedFlag = false
        if (all || half) childCheckedFlag = true
        !childCheckedFlag && this.childNodes.forEach(item => {
          if (item.checked) {
            childCheckedFlag = true
            return
          }
        })
        if (childCheckedFlag) {
          this.checked = !value
          return
        }
      }

      this.indeterminate = value === 'half'
      this.checked = value === true

      // if (!(this.shouldLoadData() && !this.store.checkDescendants)) {
      //   const { all, allWithoutDisable } = getChildState(this.childNodes)

      //   if (!this.isLeaf && (!all && allWithoutDisable)) {
      //     this.checked = false
      //     value = false
      //   }

      //   const handleDescendants = () => {
      //     if (deep) {
      //       const childNodes = this.childNodes
      //       for (let i = 0, j = childNodes.length; i < j; i++) {
      //         const child = childNodes[i]
      //         passValue = passValue || value !== false
      //         const isCheck = child.disabled ? child.checked : passValue
      //         child.setChecked(isCheck, deep, true, passValue)
      //       }
      //       const { half, all } = getChildState(childNodes)
      //       if (!all) {
      //         this.checked = all
      //         this.indeterminate = half
      //       }
      //     }
      //   }

      //   if (this.shouldLoadData()) {
      //   // Only work on lazy load data.
      //     this.loadData(() => {
      //       handleDescendants()
      //       reInitChecked(this)
      //     }, {
      //       checked: value !== false
      //     })
      //     return
      //   } else {
      //     handleDescendants()
      //   }
      // }

      const parent = this.parent
      if (!parent || parent.level === 0) return

      if (!recursion) {
        reInitChecked(parent)
      }
    } else {
      this.indeterminate = value === 'half'
      this.checked = value === true

      // 父子不关联，直接返回
      if (this.store.checkStrictly) return

      // 父子关联
      if (!(this.shouldLoadData() && !this.store.checkDescendants)) {
        const { all, allWithoutDisable } = getChildState(this.childNodes)

        if (!this.isLeaf && (!all && allWithoutDisable)) {
          this.checked = false
          value = false
        }

        const handleDescendants = () => {
          if (deep) {
            const childNodes = this.childNodes
            for (let i = 0, j = childNodes.length; i < j; i++) {
              const child = childNodes[i]
              passValue = passValue || value !== false
              const isCheck = child.disabled ? child.checked : passValue
              child.setChecked(isCheck, deep, true, passValue)
            }
            const { half, all } = getChildState(childNodes)
            if (!all) {
              this.checked = all
              this.indeterminate = half
            }
          }
        }

        if (this.shouldLoadData()) {
        // Only work on lazy load data.
          this.loadData(() => {
            handleDescendants()
            reInitChecked(this)
          }, {
            checked: value !== false
          })
          return
        } else {
          handleDescendants()
        }
      }

      const parent = this.parent
      if (!parent || parent.level === 0) return

      if (!recursion) {
        reInitChecked(parent)
      }
    }
  }

  getChildren(forceInit = false) { // this is data
    if (this.level === 0) return this.data
    const data = this.data
    if (!data) return null

    const props = this.store.props
    let children = 'children'
    if (props) {
      children = props.children || 'children'
    }

    if (data[children] === undefined) {
      data[children] = null
    }

    if (forceInit && !data[children]) {
      data[children] = []
    }

    return data[children]
  }

  updateChildren() {
    const newData = this.getChildren() || []
    const oldData = this.childNodes.map((node) => node.data)

    const newDataMap = {}
    const newNodes = []

    newData.forEach((item, index) => {
      if (item[NODE_KEY]) {
        newDataMap[item[NODE_KEY]] = { index, data: item }
      } else {
        newNodes.push({ index, data: item })
      }
    })

    oldData.forEach((item) => {
      if (!newDataMap[item[NODE_KEY]]) this.removeChildByData(item)
    })

    newNodes.forEach(({ index, data }) => {
      this.insertChild({ data }, index)
    })

    this.updateLeafState()
  }

  loadData(callback, defaultProps = {}) {
    if (this.store.lazy === true && this.store.load && !this.loaded && (!this.loading || Object.keys(defaultProps).length)) {
      this.loading = true

      const resolve = (children) => {
        this.loaded = true
        this.loading = false
        this.childNodes = []

        this.doCreateChildren(children, defaultProps)

        this.updateLeafState()
        if (callback) {
          callback.call(this, children)
        }
      }

      this.store.load(this, resolve)
    } else {
      if (callback) {
        callback.call(this)
      }
    }
  }
}
